1. Field of Invention
The present invention relates to the technology of the transmission and determination of control signal, and more particularly to a power line communication control system adapted for single-wire and a method thereof.
2. Related Art
Lamp has already become an indispensable appliance in daily life. For house plan or home plan, lamp also plays an important role. The interface of the lamp-holder is generally configured on the wall or ceiling. The interface of the lamp-holder is not only used for disposing the lamp, such as wall lamp, chandelier, fluorescent lamp, but also for disposing ceiling fans or a ceiling fan with integrated light fixtures. Moreover, the lamp or the ceiling fans is with multi-level control function. FIG. 1 illustrates a circuit block diagram depicting a lamp with multi-level control function according to a conventional art. Referring to FIG. 1, the lamp with multi-level control function comprises a lamp switch 101, a multi-level control circuit 102, a fluorescent lamp 103 and a night light 104. The multi-level control circuit 102 is used for detecting number of times for turning on the lamp switch 101. At the first time that lamp switch 101 is turned on, the output terminal 10A outputs the AC voltage/current, and the output terminals 10B and 10C are high impedance. Thus, the fluorescent lamp 103 is turned on, and the night light 104 is kept in off state. When the lamp switch is turned on second time, the output terminal 10B outputs the AC voltage/current, and the output terminals 10A and 10C are high impedance. Thus, the fluorescent lamp 103 is turned off, and the night light 104 is turned on. When the lamp switch is turned on third time, the output terminal 10C outputs the AC voltage/current, and the output terminals 10A and 10B are high impedance. Thus, the fluorescent lamp 103 and the night light are turned on at the same time.
However, the disadvantage of the multi-level control lamp is that user must turn off and then turn on the lamp switch 101 to switch the levels. The method for switching the levels would cause interruption of the AC current/voltage repeatedly, and the lamps would be first extinguished then be lit. If user mis-operates the lamp switch 101, user has to perform to turn on and off the lamp switch 101 more times. Another level switching method is to set a drawstring on the lamp or the ceiling fan, and the levels controlling is by whether the drawstring is pulled or not. However, to set a drawstring on the lamp or the ceiling fan should consider whether user can pull the drawstring or not. Moreover, the drawstring in a living room may block the sight.
According to the issues arising from the above-mentioned prior art, industry also propose a solution now. FIG. 2 illustrates a wiring diagram depicting a lamp with multi-level control function according to a conventional art. Referring to FIG. 2, the wiring diagram of the lamp includes a live wire L, a neutral wire N, a lamp 201, a wall lamp line 202, a lamp switch SW, an interface circuit 204 and a control line 203. User can switch the levels of the lamp 201 through the interface circuit 204 and the control line 203. However, people having ordinary skill in the art should know that the extra control line 203 should be configured in the wall in order to install the interface circuit 204. This wiring configuration is more complex. Also, the interface circuit 204 coupled to the control line 203 belongs to weak current circuit. If the control line 203 is configured with the wall lamp line 202, it may have doubts about security.
The other solution is to use a wireless control method. The method can reduce the wiring. However, an extra wireless signal transmitter is required, and the lamp needs a wireless signal receiver as well. This design causes high price of the lamp.